Name: Vladyslav Shtabovenko Date: 01/26/17-01:34:50 PM Z


Hi,

at the moment I’m not able to reproduce this bug.

With FeynCalc 9.2.0 on Mathematica 11 I get

«FeynCalc`
int = PaVe[1, 2, {0, s, 0}, {mf^2, mf^2, mf^2}];
res = PaVeReduce[int]

-(((4 - D) PaVe[0, {s}, {mf^2, mf^2}])/(2 (2 - D) s)) - (
  2 mf^2 PaVe[0, {0, 0, s}, {mf^2, mf^2, mf^2}])/((2 - D) s)

which can be checked e.g. with FeynHelpers

$LoadAddOns = {“FeynHelpers”};
«FeynCalc`

int = PaVe[1, 2, {0, s, 0}, {mf^2, mf^2, mf^2}];
res = PaVeReduce[int]

PaXEvaluate[int] === PaXEvaluate[res]

True

to be the correct decomposition.

Cheers,
Vladyslav

Am 26.01.2017 um 12:45 schrieb Davide Racco:
> Hi,
> first of all I thank you for making available this extremely useful package.
> I would like to report what could be a possible bug in the function PaVeReduce in FeynCalc 9.2.0.
>
> If I try to PaVeReduce the function
> PaVe[1, 2, {0, s, 0}, {mf^2, mf^2, mf^2}]
> with FeynCalc 8.2.0 (I had it installed on my previous laptop) the output is
> (mf^2*PaVe[0, {0, 0, s}, {mf^2, mf^2, mf^2}])/s + 1/(2 s)
> while now with FeynCalc 9.2.0 I obtain just the first term
> (mf^2*PaVe[0, {0, 0, s}, {mf^2, mf^2, mf^2}])/s
>
> I checked what should be the right answer by evaluating the three expressions with LoopTools 2.13 (for mf->173, s->400), and I obtain respectively
> -1.39467*10^-6
> -1.39467*10^-6
> -0.00125139
> therefore the output of FC 8 seems to be the right one.
>
> Thanks for your help,
> Davide Racco
>